Daikin Industries, Ltd.

You Tomiyama

Tatsuya Makino

Naoki Moroi

An air conditioning apparatus includes a refrigerant circuit, a suction temperature sensor, and a controller. In the refrigerant circuit, a compressor, a radiator, an expansion valve, an evaporator, and an accumulator are connected in order. The controller controls the number of revolutions of the compressor and the opening degree of the expansion valve. On determination that a refrigerant and a lubricating oil are separated inside the accumulator based on a detection result of the suction temperature sensor, the controller executes control of step to decrease the number of revolutions of the compressor, and executes control of step to set the opening degree of the expansion valve to a predetermined opening degree.

Refrigeration apparatus

A refrigerant cycle apparatus is configured to suppress extension of defrost time. The refrigerant cycle apparatus includes: a refrigerant circuit; a first temperature sensor configured to measure first refrigerant temperature between the main heat exchange unit and the pressure loss portion; a second temperature sensor configured to measure second refrigerant temperature between the pressure loss portion and the expansion mechanism; and a controller configured to control the flow direction switching mechanism to switch between normal operation and defrost operation. The controller has control modes for the defrost operation, including a control mode of terminating the defrost operation based on the first refrigerant temperature and a control mode of terminating the defrost operation based on the second refrigerant temperature.

Heat pump with defrost termination based upon system temperatures

A refrigeration apparatus includes a refrigerant circuit including a compressor, an outdoor heat exchanger, an expansion valve, and an indoor heat exchanger connected to each other, the refrigerant circuit being capable of executing at least a heating operation by circulating a refrigerant through the refrigerant circuit, and a control unit configured to start a defrosting operation for melting frost formed on the outdoor heat exchanger when a first defrosting start condition is satisfied in a case where a predetermined premise situation is not established and start the defrosting operation when a second defrosting start condition stricter than the first defrosting start condition is satisfied in a case where the predetermined premise situation is established. The predetermined premise situation is at least either a situation relating to unlikelihood of formation of frost on the outdoor heat exchanger progressing or a situation where a load of the heating operation is large.

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Osaka, Japan

You Tomiyama